I have a Pulsar II card that I recently purchased along with the Pro Pack special. This is truly a great system for anyone who does electronic composing, or wants to expand their home recording setup.
The hardware is top notch. I have the Plus variation (which includes balanced analog, AES / EBU, and 2x ADAT I/O connections and this integrates perfectly with my Pro Tools setup on a Mac G4.
The software environment is deep, no doubt about it....but it is also extremely flexible. Audio routing, effects, mixing, and virttual instruments are handled by the onboard DSP chips with very little overhead on your native CPU...and very low latency. I run my setup synced to Pro Tools with 3ms of latency on the software synths.
Creamware just released SFP 3.1, which is a software upgrade and effort to unify all of their hardware cards under the same software. Works pretty well on my Mac with OS 9.2.2 - no crashes so far, and only minor problems for such a large software upgrade. Creamware states they will be releasing an OSX version soon.
One of the strong points (in my view) of this system is the quality of the virtual devices available. These are some of the best synths, samplers, etc. available anywhere. The sound is fantastic.....the Miniscope (a software version of the Minimoog) is one of the best emulations I have ever heard.....just perfect. There is also a Juno 106 model, a Prophet VS model, and others. Also, many free devices exist for download and can be incorporated into your setup.
I like the system so much, I am getting ready to add a SRB board (Sonic Rocket Booster)...which is basically a second card (without hardware I/O) but with 15 extra DSP chips on board. This card will basically interface with the Pulsar card and allow a combined total of 21 !! DSP chips for use.
Bottom line: If you don't mind a system that is deep and expansive...then you should really check into the Pulsar / Scope platform. The value for what you get is outstanding.